Motorboat driving mechanism



Nov. 14, 1939.

H. v. M. HALL 2,179,626

MOTORBOAT DRIVING MECHANISM 'F'iled Oct. 24, 1958 2 Sheets-Sheet 1INVENTOR. HARRY V. M. HALL.

WXJ

ATTORNEY.

Nov. 14, 1939.

MOTORBOAT DRIVING MECHANISM Filed Go t. 24; 1938 2 SheetsSheet 2INVENTOR. HARRY V. M. HALL.

BYWJW ATTORNEY.

H. v. M. HALL 2.179.626

Patented Nov. 14, 1939 Nl'ED STATES PATENT OFFICE 2,179,626 MOTORBOATDRIVINGMECHANISM Harry V. M. Hall, Berkeley, Calif.

Application October 24, 1938, Serial No. 236,598

11 Claims.

My invention relates to motorboats and more especially to the drivingmechanism for motorboats used. mainly by fishermen, as in trolling forfish, or otherwise.

In trolling for fish, for instance, the fisherman sits in a boat and thebait or lure is pulled slowly through the water.

It is necessary to be able to control the speed of the boat so as tomove the bait or lure through the water at the speed that is thought toproduce the best results at that time and under those conditions.

A small quiet boat is best; it need not have high speed, but it shouldbe able to be put into neutral, forward, or reverse with certainty andspeed, for ease in starting the engine, and for ease in approaching awharf, sunken rocks, sand bars, uneven shore lines, mud banks oranything else likely to be approached by a fisherman.

The object of this invention is to provide for a small fishermans boat,or any other boat, a drive mechanism which may, at any time, beinstantly and easily put into neutral, forward, or reverse, for ease instarting the engine and for perfect and instant control of the movementsof the boat.

A further object is to provide such a drive mechanism in which the poweris transmitted, in either forward or reverse, through friction.

A further object is to provide such a drive mechanism in which thefrictional engagement of the drive is mainly maintained in both forwardand reverse, by the thrust or drive of the propeller.

A further object is to provide such a drive mechanism in which theforward end of the propeller shaft tube is above the level of the water,and grease supplied to the propeller shaft tube front hearing willpreclude the passage of water through the tube, so that no water-tightpacking gland is required for the propeller shaft.

A further object is to provide such a drive mechanism in which theengine and control mechanism may be installed in a water-tightbulkheaded compartment or similar container, which is automaticallypumped dry bythe drive mechanism, whenever water in any Way may enter.

A further object is to provide such a drive mechanism which will remainin either neutral, forward, or reverse position, as set.

A further object is to provide such a drive mechanism having all theabove good features and which may be instinctively controlled by theforward position of the control lever to provide forward movement, bythe rearward position of the lever to provide rearward movement, and bythe intermediate position of the lever to provide the neutral position.

A further object is toprovide a drivemechanism having all the abovefeatures, and whose 5 operation at all times is practically silent, 'sothat the fish will be disturbed or alarmed as little as possible by theoperation of the boat.

A further object is to provide'a drive mechanism having all the abovegood features and. 0 which is cheap and simple to manufacture, toinstall, and to maintain in proper working condition.

A further object is to provide such a drive mechanism in which theengine will, without 15 metallic gearing, be able to revolve about twicefor each revolution of the propeller shaft, or some other multiplethereof, whereby, when the engine is throttled down to run slowly, theboat speed willbe very low, and whereby even a small 0 engine, whenopened up, will be able'to run at a high enough speed to deliversufiicient power to drive the boat at a fair speed through the water.

'I attain all of the above objects by providing a longitudinally movablepropeller shaft and pro- 5 peller, having two driven friction "diskssecured to the shaft and spaced apart a distance slightly greater thanthe diameter of the drive pulley of the engine, which drive pulley islocated between the two disks and is covered with leather, rubber, 30 orother proper friction drive material, by providing means to lock thepropeller shaft in the forward, rearward, or neutral positions to giveforward, reverse, or neutral, by providing watertight bulkheads orpartitions between which the 3 engine and drive mechanism are installed,by providing a propeller shaft tube surrounding the propeller shaft andpassing through the bottom of the boat and through the rearward of saidbulkheads or partitions, and by providing for at gm least one of saiddisks a proper water collecting scoop and a connected discharge tubethrough which any water in said compartment will be thrown out of theboat by the revolving disk.

All of the above will be more clearly understood 4 by reference to thedrawings, inwhich- Figure 1 is a plan view in partial section, of a boatprovided with my invention.

Figure 2 is a side elevation in partial section of Figure 1 and showingthe location of thewater 0 line.

Figure 3 is a cross section looking toward the rear of Figure 1 throughthe engine'compartment, showing the location of the engine and inpartial section the disk used for water throwing, its 5' stationarywater-collecting scoop and the connected water discharge tube or pipe.

Figure 4 is an enlarged view of the control device and spring lock,located between the two driven disks and the two propeller shaftbearings.

Figure 5 is a transverse sectional view through the control levershowing the spring locking means, the guide for the spring, and theassociated parts.

Figure 6 is a view of a modified form of driving mechanism, in which thedisks and the engine driving pulley are of the bevel type to providesubstantially perfect rolling contact.

In Figures 1 and 2, the boat I, has the propeller shaft 2, and thepropeller 3. To the shaft 2 is securely attached by proper keys, pins,or set screws, or any or all of them, the driven disks 4 and 5, whichmay be of metal, plastic, or any other proper material.

The propeller shaft 2 is properly mounted in the bearings I, 8, and 8'.More or other bearings may be employed if desired.

The propeller shaft tube 9 surrounds and has slight clearance with thepropeller shaft 2 and passes through the rear bulkhead 10 as a part ofthe bearing 8, and also passes through the bottom of the boat I.

. A water-tight fit is provided in any proper manner, through both thebulkhead Ill and the boat bottom.

The forward end of the tube 9 where is passes through the bulkhead If!at the bearing 8, is above the water level L-L, as seen in Figure 2, sothat ordinarily no water will get into the boat along the propellershaft 2.

But the grease cup 9 by supplying grease to the bearing 8 assists in theexclusion of the water due to waves or other causes which might rise inthe tube 9 above the water level. To the rear of the bearing 8 the tube9 has slight clearance with propeller-shaft 2, which is not clearlyshown in the drawings.

The engine H is provided with the pulley !2 whose outer face is coveredwith leather, rubber, brake lining or other proper friction drivematerial, or the pulley 12 may if desired be made mainly from suchmaterial, and it is located between the disks 4 and 5, and between thebulkheads l0 andlfl'.

The engine crankshaft extends transversely of the boat or it may be saidto be in an approximately transverse plane, or in a plane substan tiallyat right angles to the propeller shaft 2.

When the shaft 2 and the propeller 3 are in their forward positions, thedisk 4 contacts the pulley l2 and the revolution of the engine as shownby the curved arrow l3 revolves the propeller shaft 2 by frictionbetween the pulley l2 and the disk 4, as shown by the curved arrow M.

This revolution of the propeller shaft 2 causes the propeller 3 to drivethe propeller shaft 2 forward and this force causes the disk 4 to beheld against the pulley l2, so the drive of the propeller increases thefrictional contact between the disk and the engine pulley.

In other words, the entire drive of the propeller against the boatpasses through the frictional engagement of the driven disk and theengine pulley.

Thus the pressure between the pulley l2 and the disk 4 is alwaysproportional to the power being exerted by the propeller 3; andconsequently the more power being exerted, the greater will be thepressure at this frictional driving contact.

When the propeller shaft 2 and the disks 4 and 5 are in the rearwardposition, the pulley I2 will contact the disk 5 and the propeller shaft2 will be revolved in the direction opposite to the arrow I4, and thepropeller 3 will pull the shaft 2 rearwardly thus pulling the disk 5into contact with the pulley I2. This contact and the resultingfrictional engagement of the pulley l2 with the disk 5 will be inproportion to the power exerted through the propeller 3, just as whenthe driveis forward the contact is maintained with the disk 4.

It will be seen from the above that the propeller thrust, whetherforward or rearward is transverse with respect to the engine shaftinstead of axially along the shaft, as is usual.

The control may employ any proper construction by which the propellershaft, propeller and driven disks may be moved and set in the forward,reverse, or neutral positions. One of such constructions is shown inFigures 4 and 5. It consists of a roller l5 pivotally mounted on a twolegged lever l6, whose two legs are pivotally mounted at their lowerends on a clip or member H, which is properly attached to the boat I.

When the upper end of the lever i6 is pushed forward,which is theinstinctive thing to do when forward speed is desired, to the position Fshown by dotted lines in Figure 4, the roller l5 bears against theforward disk 5, pushing the shaft 2 forward until the disk 4 bearsagainst the driving pulley l2, causing the shaft 2 to revolve so as todrive the boat forward, and this thrust from the propeller 3 to the disk4 and to the pulley l2 propels the boat and provides the necessaryfrictional engagement between the disk 4 and the pulley l2.

When in the forward position F the lever i6 is held in that position bythe compressed spring I 8, which is held in place by the shoulderedguide pin l9. The guide pin l9 projects through a free fitting hole inthe spherically faced washer l9 and through the loose fitting hole inthe lever l8 as shown in Figure 5.

The spherically faced washer l9" fits over the reduced end of the guidepin l9 and between the shoulder of the pin I9 and the spherical face inthe control support member 20. Or the washer l9 and the pin l9 may bemade as one piece if desired.

The spring I8 holds the two spherically faced washers in place againsttheir spherical cups in the lever l6 and the member 20 respectively.

, Thus movement of the lever I6 is permitted and its movement fromeither the forward or the stinctive movement if reverse is desired. Inthis position the roller I5 bears against the disk 4, pushing the shaft2 rearwardly until the disk 5 bears against the engine pulley l2, andthis position is maintained by the compressed spring l8.

This causes the shaft 2 to revolve so as to drive the boat I rearwardly,and this drive of the propeller 3 forces the disk 5 with more forceagainst the pulley l2, in fact all the force thrusting the boat throughthe water is applied against the pulley I 2.

When in the reverse position R the lever i6 is also held in thatposition by the compressed spring I8, just as when the lever I6 is inthe forward position F.

The control support member 20 may be mounted upon the two bulkheads Illand ID as shown in Figure 4, or may be properly mounted upon the boat Iin any other manner that will properly locate the member so that it mayperform its duties even if changed in form somewhat.

A spring guide H, with a slight depression 22 at its central portion, isproperly mounted upon the support member 20, so that the lever I6 isspring-held between the guide 2! and the member Bil when the lever it isin either the forward or the reverse position. The depression 22 in theguide 2i serves to prevent the lever it from movement out of the neutralposition shown by solid lines in the N position in Figure 4. That is,the movement of the lever It in either direction from the neutralposition can only be accomplished by a slight springing of the guide 2!away from the support member 26.

It will be noted that as the roller l5 operates very close to the axisof the propeller shaft 2, and as the roller i5 is of comparatively largediameter, it will revolve comparatively slowly when in action withpractically no drag on the mechamsm.

The tension of the spring it in either of the cit-center positions isenough to cause a light contact between either the disk 4 or the disk 5and the pulley l2.

When this light contact causes the propeller shaft 2 to revolve theresulting drive or thrust of the propeller 3 provides the necessarydriving contact between the pulley i2 and the disk it then contacts.

When the lever 86 is put in the neutral position, it will stay therebecause it takes a slight pressure to move the lever iii out of thedepression 22 and between the guide 2! and the support member 28, ineither direction.

When the lever i5 is in either the forward or the rearward position, itwill stay as set (should the engine be shut off) because the spring l8pushes it to contact the disk i or the disk 5 as the case may be, theangle of the spring i8 and the guide pin 19 being accommodated for by Lthe spherically faced washers.

Yet when the lever i6 is in any of the three positions, it can be easilyand instantly moved to either offthe two other positions since there areno gears that must be engaged, and wherever the lever is moved it willremain.

Moving the lever it to the intermediate or neutral position, locks thelever in the depression 22 of the guide 2i and thus holds both disk land disk 5 spaced from the pulley l2.

The above details show. one manner in which thecontrol of forward,reverse and neutral may be obtained, but any mechanic will understandthat any other proper construction may be employed so long as the sameor similar control results are obtained.

Should waves ever cause water to pass up through the tube 9 and into thecompartment between the bulkheads i ii, and It, in spite of the end ofthe tube 9 being above the water level and in spite of the grease in thebearing 2 at the upper end of the tube 9, or if water ever comes overthe sides of the boat and into the engine compartment between the twobulkheads, this water will be automatically removed or bailed out, asfollows:

The disk 4 revolves with its periphery quite close to the bottom of theboat l.

The water scoop 25 is properly positioned and attached to the bottom ofthe beat I below the disk 1, and is connected to the pipe 26 whichpasses through the side of the boat 1 above the water level.

The scoop- 25 is wide enough longitudinally of the boat 0 to permit themovements of the disk t to take place within the front and rear edges ofthe scoop.

Any water in the engine compartment will collect at its-deepest pointwhich is directly under the center of. the disk i and within the scoop25.

As the disk 4 revolves any water its periphery contacts will be thrownalong the scoop 25 to the pipe 26 and out of the boat I.

This will maintain the engine compartment between the bulkheads l0 andiii in a dry condition at all times when the engine is running.

Since the boat is driven in reverse a very small proportion of the time,no scoop is shown for bailing out the engine compartment when the boatis going in reverse. But, if this is ever required any mechanic will atonce see that all that is required is another scoop in line with thepresent scoop and extending to the other side of the boat, so that whenthe disk 4 revolves in the opposite direction (reverse) it will throwthe water out through this reverse scoop and its connected pipe and outof the boat.

Or, if the engine and propeller are built to run in directions oppositeto those indicated by the arrows l3 and M, when going forward, then thescoop and pipe should be placed on the other side of the boat from thatshown in the drawings.

It will thus be seen that all my objects are attained, and that thedevice is both simple and cheap, and its control is entirelyinstinctive, since the control lever is merely moved forward for goingahead, rearward for going in reverse, and midway for standing still.

It will be observed that the disks 4 and 5 are about twice the diameterof the pulley 52, so that when the engine I! is throttled down to runslowly, the propeller 3 will then travel at about half the speed of theengine, and this will provide the slow speed so desired for some fishingconditions. Yet, because of. this two to one reduction in the drive, thesmall engine used may get up to its rated speed where it will produceenough power to revolve the propeller at half engine speed.

And the amount of pressure for a proper friction drive is alwaysautomatically provided since the entire thrust of the propeller inpushing the boat through the Water maintains the contact between theengine pulley and the disk it then contacts.

The drive is practically silent, so that ii a good and proper mufller isemployed which discharges directly 'into the air and not into the water,the boat will not alarm or disturb the fish.

In approaching mud banks, sand bars, sunken rocks or other hazards, thedrive provides the most instantaneous control of the boats movements.And wherever the drive control is set, it will remain.

A modified form of my friction drive is shown in Figure 6.

The friction drive shown in Figures 2, and 3 has true rolling contactbetween the pulley l2 and the disks 6 and 5 only at the center line ofthe face of the pulley I2.

Toward the propeller 2 from this center line, the pulley face travelsslightly too fast for true rolling contact; and on the other side ofthis center line of the face of the pulley i2, the pulley face travelsslightly too slowly, for true rolling contacts with either the disk 5 orthe disk 5.

In other wordson either side of this center line there must be someslight slipping between the face of the pulley l2 and the face of eitherdisk 4 or disk 5. It is a well known fact that once slipping startsbetween two friction drive surfaces, the coefficient of friction at oncegreatly decreases. This is illustrated clearly in driving an automobile.In either pulling or using the brakes, once the tires begin to sliplittle can be done.

The construction shown in Figure 6 by providing only true rollingcontact with no inherent slipping between the two surfaces, willincrease the power that may be transmitted, other things being equal.

The bevel disks 4' and 5' have true rolling contact with the bevel drivepulley I2. It will be noted that the roller IS in this construction,also has an angled face to fit the angled faces of disks 4' and 5'.

As shown in Figure 6, the same ratio, two to one, is maintained as shownin Figures 1, 2, and 3.

However, different ratios may be easily obtained, as any mechanic willunderstand, by variation in the bevel angle and proportion of the parts.

By the use of the bevel construction true rolling contact may beobtained, with probably less slipping and less wear upon the surfaces.

Having now described my invention, what I claim as new and desire toprotect by Letters Patent, is as follows:

1. In a motorboat, a front and a rear bulkhead joining the two sides ofthe boat, a propeller shaft longitudinally movable and carried in properbearlugs and provided with a propeller and with two spaced driven diskslocated between said bulkheads, a tube surrounding said propeller shaftand having water-tight passage through the bottom of the boat andtherearward of the two bulkheads, said tube where it passes through saidbulkhead being above the water level, an engine with a crankshaftlocated in an approximately transverse plane of the boat and providedwith a friction drive pulley located between said driven disks, wherebyengagement between the drive pulley and one disk will propel the boatforward and engagement between said drive pulley and the other disk willpropel the boat rearwardly, and means carried by the boat to move thepropeller shaft longitudinally to effect either of said engagements, orto hold said shaft in its intermediate position, selectively.

2. In a motorboat drive mechanism having an engine provided with afriction drive pulley, and a longitudinally movable propeller shafthaving two driven disks located on opposite sides of said drive pulley,whereby the forward position of the propeller shaft will engage therearward disk and the drive pulley and propel the boat forward, and therearward position of the propeller shaft will engage the forward diskand the drive pulley to propel the boat rearwardly, and in bothpositions the action of the propeller will increase the frictionalengagement of the drive pulley and the disk with which it is in contact,and control means carried by the boat for moving the propeller shaftlongitudinally and consisting of a spring-held lever provided with meansto put endwise pressure on said propeller shaft in either forward orrearward direction, and a spring lock having a lever-receivingdepression for locking the lever resiliently in the neutral position.

- 3. In a motorboat drive mechanism, a boat having an engine compartmentlocated between bulkheads, a longitudinally extending rotating shaftdriven by the engine and having a member of larger diameter securedthereto, and whose outer face is adjacent the bottom of said boat, andscoop means adjacent said member to catch water thrown therefrom andpipe means attached to said scoop means to discharge said water throughone side of said boat above the water level.

4. In a motorboat, front and rear bulkheads joining the two sides of theboat, a propeller shaft longitudinally movable and carried in properbearings and. provided with a propeller and with two spaced driven diskslocated between said bulkheads and at least one of said disks having itsrim located adjacent the bottom of said boat whereby to throw water fromthe bottom of the boat, a tube surrounding said propeller shaft andhaving water tight passage through the bottom of the boat and therearward of the two bulkheads, said tube where it passes through saidbulkhead being above the water level, water catching-means adjacent saidwater throwing disk to catch water thrown from said disk and dischargeit outside said boat, an engine with a crankshaft located in anapproximately transverse plane of the boat and provided with a frictiondrive pulley located between said driven disks, whereby engagementbetween the drive pulley and one disk will propel the boat forward andengagement between said drive pulley and the other disk will propel theboat rearwardly, and means carried by the boat to move the propellershaft longitudinally to effect either of said engagements, or to holdsaid shaft in its intermediate position, selectively.

5. In a motorboat drive mechanism havingan engine provided with afriction drive pulley, and a longitudinally movable propeller shafthaving two driven disks, at least one of said disks having its rimrotate adjacent the floor of the boat where it will throw any water thatmay collect, means adjacent said water throwing disk to catch anddischarge outside the boat water thrown from said disk, said two diskslocated on opposite sides of said drive pulley whereby the forwardposition of the propeller shaft will engage the rearward disk and thedrive pulley and propel the boat forward, and the rearward position ofthe propeller shaft will engage the forward disk and the drive pulley topropel the boat rearwardly, and in both positions the action of thepropeller will increase the frictional engagement of the drive pulleyand the disk with which it is in contact, and control means carried bythe boat for moving the propeller shaft longitudinally and consisting ofa spring-held lever provided with means to put endwise pressure on saidpropeller shaft in either forward or rearward direction, and a springlock having a lever-receiving depression for locking the leverresiliently in the neutral position.

6. In a motorboat drive mechanism a circular revolving member adapted tothrow water which comes into contact with its rim which is locatedadjacent the bottom of the boat, in the direction in which the rim istraveling adjacent the bottom of the boat, water receiving meansadjacent said member adapted to catch water thrown from the rim of saidmember and discharge the water thus caught outside the boat.

7. In a motorboat friction drive mechanism, a circular revolving memberadjacent the driving friction contact means of said drive mechanismconstructed and arranged to throw any water which may come into contactwith its rim in the general direction in which the rim is travelingadjacent the floor of said boat, and water receiving means adjacent saidmember constructed and arranged to catch water thrown from said memberand discharge the water thus caught outside the boat, whereby the saidfrictional contact means will at all times be prevented from beingsubmerged and will be kept in good working condition.

8. In a motorboat friction drive mechanism, a compartment in the boat, afriction drive mechanism in said compartment, a propeller shaft in atube having a water tight passage from outside the boat into saidcompartment, where the tube is located above the water level, and acircular revolving member adjacent the frictional contact drive means ofsaid drive mechanism constructed and arranged to throw water which maycome into contact with its rim in the general direction in which the rimis traveling adjacent the bottom of said compartment, and waterreceiving means adjacent said member constructed and arranged to catchwater thrown from said member and discharge the water thus caughtoutside the boat, whereby the said fric tional contact means and saidcompartment will at all times be kept dry.

9. In a motorboat drive mechanism having an engine mounted upon theinside of the bottom of the boat and provided with a crankshaft having afriction drive member, and a longitudinally movable propeller shafthaving two friction driven members located on opposite sides of saidfriction drive member, whereby the forward position of the propellershaft will engage the rear- Ward driven member and the drive member andpropel the boat forward, and the rearward position of the propellershaft will engage the forward driven member and the drive member topropel the boat rearwardly, and in both positions the action of thepropeller will increase the frictional engagement of the drive memberand the driven member with which it is in contact, one of said drivenmembers being constructed and arranged to throw Water which may comeinto contact with its rim in the general direction in which the rim istraveling adjacent the inside bottom of said boat, water receiving meansadjacent said water throwing member constructed and arranged to catchwater thrown from said member and discharge the water outside the boat,manually operated means having a handreceiving portion, to move thepropeller shaft longitudinally to effect either of said engagements orto locate said shaft in its intermediate position selectively andincluding a pivotal mounting on the boat on the opposite side of saidcrankshaft from said hand-receiving portion, whereby the forward andrearward positions of said manually operated means will correspond tothe forward and rearward positions of said propeller shaft, resilientmeans to hold the said shaft as set in either its forward or itsrearward position and to increase said frictional engagements, andrecessed means to resiliently hold said manually operated means in itsintermediate position.

10. In a motorboat drive mechanism having an engine mounted upon theinside of the bottom of the boat and provided with a crankshaft having afriction drive member, and a longitudinally movable propeller shafthaving two friction driven members located on opposite sides of saidfriction drive member, whereby the forward position of the propellershaft will engage the rearward driven member and the drive member andpropel the boat forward, and the rearward position of the propellershaft will engage the forward driven member and the drive member topropel the boat rearwardly, and in both positions the action of thepropeller will increase the frictional engagement of the drive memberand the driven member with which it is in contact, a bulkhead extendingacross said boat to the rear of said engine and friction members, a tubeenclosing the propeller shaft and having a water tight passage throughthe bottom of the boat and through said bulkhead above the water line,manually operated means having a hand-receiving portion, to move thepropeller shaft longitudinally to effect either of said engagements orto locate said shaft in its intermediate position selectively andincluding a pivotal mounting on the boat on the opposite side of saidcrankshaft from said hand-receiving portion, whereby the forward andrearward positions of said manually operated means will correspond tothe forward and rearward positions of said propeller shaft, resilientmeans to hold the said shaft as set in either its forward or itsrearward position and to increase said frictional engagements, andrecessed means to resiliently hold said manually operated means in itsintermediate position.

11. In a motorboat drive mechanism having an engine mounted upon theinside of the bottom of the boat and provided with a crankshaft having afriction drive member, and a longitudinally movable propeller shafthaving two friction driven members located on opposite sides of saidfriction drive member, whereby the forward position of the propellershaft will engage the rear- Ward driven member and the drive member andpropel the boat forward, and the rearward position of the propellershaft will engage the forward driven member and the drive member topropel the boat rearwardly, and in both positions the action of thepropeller will increase the frictional engagement of the drive memberand the driven member with which it is in contact, one of said drivenmembers being constructed and arranged to throw water which may comeinto contact with its rim in the general direction in which the rim istraveling adjacent the inside bottom of said boat, water receiving meansadjacent said water throwing member constructed and arranged to catchwater thrown from said member and discharge the water thus caughtoutside the boat, a bulkhead in said boat to the rear of said engine andfriction members, a tube enclosing the propeller shaft and having watertight passage through the bottom of the boat and through said bulkheadabove the water level, manually operated means having a hand-receivingportion, to move the propeller shaft longitudinally to effect either ofsaid engagements or to locate said shaft in its intermediate positionselectively and including a pivotal mounting on the boat on the oppositeside of said crankshaft from said hand-receiving portion, whereby theforward and rearward positions of said manually operated means willcorrespond to the forward and rearward positions of said propellershaft, resilient means to hold the said shaft as set in either itsforward or its rearward positionand to increase said frictionalengagements, and recessed means to resiliently hold said manuallyoperated means in its intermediate position.

HARRY V. M. HALL.

